Many kinds of ladders and stepping-stools are known in the art. U.S. Pat. No. 4,564,203 to Ronald Williams, dated Jan. 14, 1986, discloses an aid for transporting a narrow oblong object. In his U.S. Pat. No. 3,580,601, dated May 25, 1971, Ray P. Miller discloses a skate device for transporting unwieldy, flat objects. U.S. Pat. No. 5,566,780, dated Oct. 22, 1996 was issued to Harry M. Hambrough. It describes a combination cart and ladder apparatus including a first and a second ladder assembly.
Peter DiSario's U.S. Pat. No. 5,727,799 presents a dolly for supporting a ladder during movement to a work site. U.S. Pat. No. 5,086,872 to Fan-Nam Lim discloses a foldable ladder equipped with a pair of wheels so the ladder can be converted into a push cart for transportation of various goods. In their U.S. Pat. No. 4,049,283, Brookes et al. describe a caddy for transporting a heavy ladder to a work site.
In his U.S. Pat. No. 5,382,032 dated Jan. 17, 1995 Wilson discloses a wheeled stepladder dolly. U.S. Pat. No. 5,105,908 was issued to Harvey J. Freund on Apr. 21, 1992. It reveals a kit which may be used to convert a ladder tree stand into a towable trailer that may be connected to a motorized vehicle.
U.S. Pat. No. 5,232,233 by John Jedora describes a portable wheel assembly provided with a parallel type clamping system for attachment to objects, such as the transom of a car-top boat.
U.S. Pat. No. 5,882,023 issued to William F. Swager discloses a wheeled transport device for maneuvering elongated objects in a simplified manner. In U.S. Pat. No. 3,841,437 by John W. Caughey, issued Oct. 15, 1974, a stool suitable for standing upon to reach high places is described. U.S. Pat. No. 4,063,616 to Ernest F. Gutierrez, issued Dec. 20, 1977 discloses a safety ladder assembly having a plurality of steps and at least three support feet for supporting the ladder on a horizontal surface. U.S. Pat. No. 5,082,086 was issued to James F. Kerr on Jan. 21, 1992. This patent discloses a ladder including wheels normally received off the ground, and four legs normally supporting the ladder.
In U.S. Pat. No. 127,571, Clark discloses an improvement in casters for sewing machines. Godwin describes a lifting handle attachment for wheelbarrows in his U.S. Pat. No. 5,153,966. Kinzel discloses a ladder attachment in U.S. Pat. No. 274,448. Harry Jones patented an improvement in casters of sewing machines in U.S. Pat. No. 115,060. Another sewing machine caster invention was detailed in Wilkins' U.S. Pat. No. 55,567. Overcash et al. disclosed a wheelbarrow extension handle in their U.S. Pat. No. 5,794,307. Bertke received U.S. Pat. No. 1,004,550 for his step ladder attachment. German et al. were issued U.S. Pat. No. 3,463,505 for their combined container and detachably mounted roller assembly.
The development of a simple ladder transportation system which would reduce or obviate the need for retraction, weight, size and cost, yet still allow one person to easily maneuver and transport a ladder from place-to-place without injury, would constitute a major advance and would satisfy a long felt need in the construction and maintenance industries.
U.S. Pat. No. 6,328,330, entitled “Hand truck attachment for a ladder” was issued to Haaser on 11 Dec. 2001. Haaser discloses a separate, detachable and installable device for use in combination with a ladder to generally convert a ladder to a hand truck which is capable of carrying a workman's cargo to a jobsite.